In response to the demands of consumers who are driven both by ever-escalating fuel prices and the dire consequences of global warming, the automobile industry is slowly starting to embrace the need for ultra-low emission, high efficiency cars. While some within the industry are attempting to achieve these goals by engineering more efficient internal combustion engines, others are incorporating hybrid or all-electric drive trains into their vehicle line-ups.
The electric drive trains used in electric vehicles (EVs) have proven to be highly reliable and capable of providing exceptional performance. Additionally, since electric motors generate useable torque and power over a very wide range of motor speeds, they do not require a multi-speed transmission such as those required by a conventional vehicle powered by an internal combustion engine.
While a multi-speed gearbox may not be required in a vehicle with an electric drive train, such a gearbox can be used to enhance an EV's performance, both in terms of acceleration and top speed. Accordingly, what is needed is a multi-speed gearbox that is small, lightweight, efficient and capable of handling the torque supplied by the motor in an electric vehicle. The present invention provides such a gearbox.